Atypical distyly in Psychotria goyazensis Mull. Arg. (Rubiaceae), an intramorph self-compatible species

Distyly and variation in floral traits in natural populations of Psychotria ipecacuanha (Brot.) Stokes (Rubiaceae)1

(Distyly and variation in floral traits in natural populations of Psychotria ipecacuanha (Brot.) Stokes (Rubiaceae)). Psychotria ipecacuanha is a perennial, medicinal herb that grows in clusters in the understory of humid, shady areas of the Atlantic Rain Forest of southeastern Brazil. The present study characterized the variation in floral traits among 35 clusters from three natural population...

Absence of alkaloids in Psychotria carthagenensis Jacq. (Rubiaceae).

Psychotria viridis and P. carthagenensis are often discussed in relation to the hallucinogenic beverage Ayahuasca, used for religious, medicinal and social purposes. The significance of including Psychotria species in this beverage has been understood on the basis of substantial amounts of tryptamine alkaloids detected on leaves of both P. viridis and P. carthagenensis. Nevertheless, there is a...

Raphide crystal cell development in leaves of Psychotria punctata (Rubiaceae).

The distribution and development of raphide cry8tal cells in nodulated leaves of Psychotria punctata were studied by light and electron microscopy. Crystal cells in the leaf are oriented in various ways depending on whether they occur in the spongy or palisade parenchyma. Crystals are never found within the bacterial nodules and are not concentrated around them. Developing leaf crystal cells be...

13C-NMR Spectral Data of Alkaloids Isolated from Psychotria Species (Rubiaceae).

The genus Psychotria (Rubiaceae) comprises more than 2000 species, mainly found in tropical and subtropical forests. Several studies have been conducted concerning their chemical compositions, showing that this genus is a potential source of alkaloids. At least 70 indole alkaloids have been identified from this genus so far. This review aimed to compile 13C-NMR data of alkaloids isolated from t...

Cytotoxic activity of polyindoline alkaloids of Psychotria forsteriana (Rubiaceae) (1).